Small internal combustion four cycle engines typically include a cam gear and a pair of cam lobes mounted on a camshaft. The cam gear meshes with a crankgear mounted on a crankshaft, thereby rotating the camshaft in timed relation to the engine cycle. Each rotating cam lobe then opens and closes either an exhaust or an intake valve.
It is known to form cam lobes and cam gears from a laminated stack of thin gear elements. U.S. Pat. Nos. 4,522,080 and 4,630,498 to Santi disclose a laminated wheel assembly which includes a cam lobe and a cam gear mounted on a camshaft. The cam gear is constructed of a laminated stack of flat plates which abut one another. The cam gear is press fit onto the camshaft, and only the frictional forces between the gear and the camshaft maintain the plate teeth together. The cam lobe is also constructed of a laminated stack of plates and press fit onto the camshaft in substantially the same manner to form an integral cam surface. However, the camshaft includes a serrated portion on its outside surface having tapered teeth that cut into the inner surfaces of the cam lobe and cam gear to secure the cam lobe and cam gear both axially and circumferentially thereon.
Another application of laminated plates in a small engine is shown in my U.S. Pat. No. 4,356,605. That patent discloses a crankshaft with a laminated counterweight having coaxially aligned bosses and depressions, which are pressed together and act as fastening means.
Heretofore, however, it has been necessary to machine or otherwise finish the teeth of laminated gears to ensure that they are sufficiently smooth and aligned. Because this process adds time and expense to the gear forming operation, there exists a need for laminated small engine gears formed by a speedier and less expensive method.